Stable tetrazomonoazo compounds and their preparation



Patented June 12, 1934 UNITED STATES PATENT OFFICE STABLE TETRAZOMONOAZO COMPOUNDS AND THEIR PREPARATION Heinrich Bamberger, Basel, Switzerland, assignor to firm Chemical Works formerly Sandoz, Basel, Switzerland No Drawing. Application January 2, 1931, Serial No. 506,328. In Germany January 7, 1930 6 Claims. (01. 260-69) This invention relates to the preparation of pazoaryl-p-amino compounds prepared as denew stable tetrazomonoazo compounds which are scribed in the British specification No. 275,147, very useful for the production of fast black shades tetrazotize the same in the usual Way and precipon textile fibres. itate the obtained tetrazo compound from its 1. According to the present invention it has been solution by means of the substances cited above. found that it is possible to prepare stable dry In each. case the precipitation gives good yields, tetrazomonoazo compounds by treating tetrazo even from very dilute, solutions, which are necsolutions deriving from monoazo dyestuffs of the essarily obtained by Work ng under most rational general formula conditions, and allows, therefore, to carry out the present invention on a technicalscale with H2N-p -P a great success. 7 65 wherein R-R represents a substituted or not sub- The present invention provides therefore a stituted p.p-diamino-diaryl residue and R1 asubprocess for the preparation of dry stable tetrastituted benzene or naphthalene nucleus and zomonoazo compounds which have hitherto never "wherein p means that the amino group contained been prepared nor described and which possess in the aromatic nucleus R1 must be in para-posia great interest for the production of fast black tion to the diazo-group with suitable inorganic shades on textile fibres. and organic substances, yielding with the tetrapp t i aware, h Solutions f t azomonoazo derivatives salts and double com- Zom noazo c mp s f h yp ed in go pounds that possess a smaller solubility as comt pr s nt sp fi at n hav ft n en p pared to that of their hydrochloric acid salts. du d in c u se f th ma ufa ture of p y z Substances which are suitable for carrying out y t ut until W he attempts h ve b e the present process are for instance the heavy made in Order to P p them in a y mmetal salts like zinc chloride, cadmium chloride, Th p s ty t pr u t n a stab d y tin chloride, titanium chloride, or acids like boric form could not have been foreseen and repreacid, hydrofluoboricacid, hydrofluoric acid, fiuorce s, the e o e, an invention o a great t c n cal silicic acid, fluorsulphonic acid and their double esaltsand also aryl sulphonic acids like naph- The w Solid t a p ds ay be m xed thalene-diand -trisulphonic acids, chlorobenwith par ly or totally anhy r us s lts and other jzenesulphonic acids, nitrobenzenesulphonic acid, Suitable diluents, and make it possible t upp sulphanilic acids, naphthol-sulphonic acids and e us r w th tetrezomonoezo mp unds, yi ldthe like. By adding these compounds to the solus pa a valuable m oezo 'dyetions of the tetrazotized monoazo dyestuffs cited etuiis n a most concentrated f mmed ate y above, the tetrazomonoazo compounds precipiready e use.

tate in form of their salts or double compounds The following eXamplee. W t being m taand after filtration may be dried in vacuo, yielde, illustrate the invention, the parts being y ing stable products easily soluble in water with a Weight: 7 yellow to brown coloration. On addition thereto of alkaline solutions of p-hydroxynaphthoic acid arylides, a precipitation of water-insoluble black 36,8 parts of benzidine are tetrazotized in the dyestuffs occurs, which when produced on the usual way with 100 parts of hydrochloric acid fibre possess excellent properties of fastness. of 30% strength and 27,6 parts of sodium nitrite.

The solutions containing the tetrazotized mon- To the solution thus obtained are added under oazo dyestuffs of the type cited are advantageousgood stirring at a temperature of 05 C. 35,9 ,;ly manufactured in the following way. parts of a-naphthylamine hydrochloride, dis- One molecule of a p-p'-diaminodiaryl comsolved in about 1200 parts of water, and the solupotmd is tetrazotized in the usual way and tion stirred until the formation of the intercoupled with one molecule of an amine of the mediate product has occurred. To the suspenbenzene or naphthalene series, capable of formsion of the intermediate product obtained are O' ing para-amino-azo-bodies, added 25 parts of hydrochloric acid of 30% Th thus obtained diazomonoazo compound i strength, the solution is cooled down to 0 C. then further diazotized and thereupon precipiby addi n f ce d a solution o 15 parts tated from its solution by addition of a suitable of sodium nitrite is introduced under the surquantity of the above named substances. It is face of the solution. After having stirred during also possible to start from the p-aminodiaryl- 2-3 hours, the diazotization is finished and a Example 1 nearly clear solution of the tetrazo compound is obtained.

The solution is then filtered in order to seprate impurities and the zinc chloride derivative of the tetrazo compound is precipitated in form of a brown crystalline precipitation by an addition thereto of a concentrated solution of 60 parts of zinc chloride and 100 parts of sodium chloride.

After a leave of several hours the precipitate is filtered off and dried in vacuo at a temperature of 45-50 C. The stable dark powder obtained is easily soluble in water with an orange, in concentrated sulphuric acid with a violet and in concentrated hydrochloric acid with a yellowish-brown coloration; on textile fibres impregnated with [i-hydroxynaphthoic acid arylides it yields very fast black dyeings.

If instead of a-naphthylamine o-anisidine or p-cresidine are used, similar stable tetrazo compounds are obtained. They yield with ,B-hydroxynaphthoic acid arylides fast black shades of a bit reddish tone.

p Example 2 vBy adding to the tetrazo compound solution obtainedas described in Example 1, instead of zinc chloride, 100 parts of the sodium salt of naphthalene trisulphonic acid, the naphthalene trisulphonic acid salt of the tetrazo compound separates out in form of a yellowish-brown crystalline precipitation. On further addition of some sodium chloride to the solution the precipitation can be completed. The precipitate is then -;filteredoff and dried in vacuo at a temperature of -50" C.

By replacing the benzidine used in these examples by equivalent quantities of tolidine or dianisidine and the a-naphthylamine by other amines of the benzene or naphthalene series, such as 1 amino-2 ethoxynaphthalene or p-cresidine, themethod of preparation of stable tetrazo compounds remains the same.

Example 3 To the tetrazo compound prepared in the usual way from 48,8 parts of dianisidine, 100 parts of hydrochloric acid of 30% strength and 27,6 parts of sodium nitrite is added a slightly acid solu- ;tion of 27,4 parts of 4-amino-3-methoxy-6- methylbenzene in about 1000 parts of water dissolved under addition of hydrochloric acid, and the solution thus obtained is stirred at a low temperature until the formation of the intermediary compound has taken place. After this has occurred, 25 parts of hydrochloric acid of 30% strength are added, the solution is cooled downto 0 C., and a solution of 15 parts of sodium nitrite is allowed to flow in under the surface of the solution. After stirring for 2-3 hours "'the diazotization is finished and a dark brown solution containing the tetrazo compound is obtained. After a filtration in order to separate the impurities the filtrate is treated with an excess of zinc chloride and sodium chloride, whereby the Zinc chloride double saltof the tetrazo compound precipitates in form of a brown crystalline powder, which is filtered off and dried in vacuo at 45-50 C. 7 c In the dry form it constitutes a stable brown powder which is easily soluble in water with a red-orange, in concentrated sulphuric acid with a red and in concentrated hydrochloric acid with a-brown-red coloration. With fl-hydroxynaph- 7 thoic acid arylides it yields water insoluble black dyestuffs, which, when produced on the fibre, possess excellent properties of fastness.

If, instead of dianisidine an equivalent quantity of o-tolidine is used, a dyestuff is obtained which yields reddish black shades.

Example 4 45,6 parts of mononitrobenzidine are dissolved in 1000 parts of hot water and 50 parts of hydrochloric acid of 30% strength and after cooling down to 0 C. the base is tetrazotized by adding thereto a solution of 27,6 parts of sodium nitrite. To the tetrazo solution thus obtained is slowly added at a temperature of 0-5 C. a solution of 35,9 parts of anaphthylamine hydrochloride dissolved in about 1500 parts of water. The obtained mixture is so long stirred until any free a-naphthylamine has completely disappeared. After this has occurred, 25 parts of hydrochloric acid of 30% strength are added and a solution of 15 parts of sodium nitrite is allowed to flow in under the surface of the solution at a temperature of 0-5" C. under good stirring. After some hours the formation of the tetrazo compound is finished and a dark yellow solution is obtained.

After filtration in order to separate a small quantity of insoluble impurities, the filtrate is treated with an excess of zinc chloride and sodium chloride, whereby the nitrotetrazo compound is precipitated in form of a brown-yellow crystalline precipitate, which is pressed and dried in vacuo at 4550 C. The black powder thus obtained possesses a good stability and is easily soluble in water with a yellow, in concentrated sulphuric acid with a blue and in concentrated hydrochloric acid with a yellowish-brown coloration. With [3-hydroxynaphthoic acid arylides it yields black dyestuffs insoluble in water which, when produced on the fibre, possess excellent fastness properties.

What I claim is:

1. A process for the preparation of dry stable tetrazomonoazo compounds, consisting in treating aqueous solutions of tetrazomonoazo compounds of the general formula:

wherein X represents hydrogen, alkyl, alkoxy, nitro and halogen, and Y represents a radical of a strong mineral acid, with a substance selected from the class consisting of heavy metal salts and naphthalene sulphonic acids.

3. A process for the preparation of a dry stable,

tetrazomonoazo compound, consisting, in treating an aqueous solution of the compound of the formula (FOB; 0 OH;

with a substance selected from the class consisting of heavy metal salts and naphthalene sulwith zinc chloride.

5. The new dry stable tetrazomonoazo compounds, prepared as described in claim 1, which constitute in dry state brown to black powders easily soluble in water with yellow to brown coloration and in concentrated sulphuric acid with a red to violet and blue coloration and which yield with fi-hydroxynaphthoic acid arylides water insoluble black dyestufis which, when being produced on the textile fibre, possess excellent fastness properties.

6. The new dry stable tetrazomonoazo compound, prepared as described in claim 4, which constitutes in dry state a brown powder easily soluble in water with a red-orange and in concentrated sulphuric acid with a red coloration and which yields with a fl-hydroxynaphthoio acid arylide a water insoluble black dyestufi, which, when being produced on the textile fibre, possesses excellent fastness properties.

HEINRICH BAMBERGER. 

